The candidate, Kristie Bjornson, PhD, PT, is a pediatric physical therapist and Assistant Professor of Pediatrics, University of Washington School of Medicine/Seattle Children's Research Institute. This award will establish her as an independent investigator in a patient-oriented clinical research program of interventions focused on improving the activity and social participation of persons with cerebral palsy (CP). This overarching goal will be accomplished through a five-year program of training, mentoring and research with the following specific objectives: 1) Develop knowledge and skill in the measurement of body composition, energy expenditure, ambulatory and physical activity performance and social participation within context of daily life. 2) Employ skills in a cross-sectional descriptive study testing the relationship of the ICF components. 3) Enhance understanding of orthotic prescription and biomechanics. 4) Develop methodology and pilot within a cross-sectional orthotic intervention study. 5) Expand knowledge of clinical trials methods, study management/leadership, grant development and scholarly writing. Her sponsor is an established pediatric researcher and career mentor, while her co-sponsor and advisory committee represent clinical and research expertise directly related to the study populationand career developmentplan. The research plan focuses first on defining the relationships of activity,participation (ICF) and body composition in a descriptive cross-sectional study of ambulatory children with CP. The extent outcomes at various levels of the ICF relate requires clarification in order for the ICF to be a useful framework for clinical research and practice. Secondarily, the ICF component relationships will be tested within a randomized cross-over clinical trial of solid ankle foot orthoses (SAFO) on daily ambulatory/physical activity performance and social participation on ambulatory children with cerebral palsy with novel ambulatory accelerometry measures. There is no published data defining the impact of SAFO on physical and ambulatoryactivity performance and participation in day to day life. This information will facilitate the development of a life span orthotic management algorithm for ambulatory persons with CP. RELEVANCE (See instructions): We will explore the connection between what a child with cerebral palsy does physicallyduring motor testing to what they 'actually' do during their day to day lives. The project will also test whether ankle braces help children with cerebral palsy do what they want to do when they want to do it. This information will be used to develop ankle bracing guidelines for persons with, cerebral palsy across the life span.